US 3078003 A
Description (OCR text may contain errors)
Feb. 19, 1963 K. K. KESLING REFRIGERATOR CABINET CONSTRUCTION 2 Sheets-Sheet 1 Filed July 25. 1960 jumvrm Keith K Kes/ing Fig.
Feb. 19, 1963 K. K. KESLING REFRIGERATOR CABINET CONSTRUCTION 2 Sheets-Sheet 2 Filed July 25, 1960 R o 0. mm W m e o K K WA mm 6 a K 20B} use Fig. 7 0:
United states Patent 3,078,t3i 3 REFRIGERATQR CABINET CUNSTRUC'HQN Keith K. Kesling, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Fiied July 25, 1%0, Ser. No. 44,959 3 Claims. (Cl. 220-9) This invention relates to cabinets and particularly to the construction of wall sections for refrigerator cabinets having a plastic insulating material foamed into the space between outer panels of the sections.
Some modifications of the new foamed-in-place polyurethanes have insulation characteristics sufficient to make possible low-cost, thin-walled refrigerator cabinets having lower heat leakage than former thick-Walled cabinets which were insulated with glass wool or mineral wool. It is commonly known that these new foamed polyurethanes have excellent adhesion properties, are light in weight, high in structural strength for their weight and are good insulators. However, full advantage of these properties cannot be realized by merely filling insulation spaces between panels of cabinet wall sections with these or other equivalent foamed materials because this alone does not render the use of such insulation practical. polyurethane are so great that it firmly bonds two Opposed wall or panel members of wall sections of a refrigerator cabinet to such a degree as to prevent separation of one panel from another without damaging the members beyond repair or cracking or breaking the polyurethane insulation therebetween. Such panel or wall members in wall construction or sections, particularly of refrigerator cabinets, occassionally become damaged and require replacement. This replacement cannot be accomplished if polyurethane is foamed directly between these panels because it firmly bonds to each panel and prevents their separation. Obviously, therefore, foamed-in-place polyurethane insulation material between opposed walls or panels of wall sections presents a problem in the refrigerator cabinet construction art. I contemplate to take advantage of the properties of foamed polyurethane in sulation to a substantial degree in the construction of insulated wall sections for refrigerator and other similar cabinets to overcome the problem just stated and to thereby at the same time derive other advantages therefrom.
An object of my invention is to provide for the separation of one wall or panel from another thereof in a wall section or main body portion of a cabinet irrespective of the type of insulating material confined in a space between the walls or panels.
3,ll78,0il3 Patented Feb. 19, 1953 tinuous sheet of material, to which polyurethane will not adhere or bond, over a first portion of a wall or panel of a wall section of a refrigerator cabinet so that the other or second portion of such wall or panel of the wall section can, upon being damaged, be easily removed from the first portion and readily replaced with a new one, when desired.
Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.
, shown in open position;
For example, adhesion properties of foamed Another object of my invention is to provide a divider thane insulating material foamed in place between walls or panels thereof with means in the section or body portion to prevent adhesion or bonding of this foamed material to both walls or panels whereby one wall or panel can be readily separated from the other.
A still further object of my invention is to provide for the separation of one wall or panel of a wall section or a main body portion of a refrigerator cabinet from another thereof having foamed polyurethane insulation therebetween without damaging parts of the section or FIGURE 2 is an enlarged fragmentary broken sectiona1 view taken along the lines 2-2 of FIGURE 1 showing a cabinet wall section having my invention embodied therein;
FIGURE 3 is a view similar to FIGURE 2 and shows the cabinet liner member moved part way out of the cabinet wall structure;
FIGURE 4 is an enlarged fragmentary sectional view taken along the lines 4-4 of FIGURE 1 showing an edge portion of the refrigerator cabinet door having a gasket thereon;
FIGURE 5 is an enlarged perspective view partly in section of the refrigerator cabinet door to illustrate my invention;
FIGURE 6 is a view similar to FIGURE 5 showing a modified refrigerator cabinet door structure; and
FIGURE 7 is a view similar to FIGURE 5 and 6 showing another modified refrigerator cabinet door structure.
Referring now to the drawings, for illustrating my invention, I show in FIGURE 1 thereof ahousehold refrigerator cabinet, 10 having a plurality of insulated walls or wall sections defining a food storage chamber 11 therein. Chamber 11 has a plurality of food supporting shelves 12 mounted therein and this chamber is adapted to be cooled by an evaporator of a refrigerator system associated with cabinet 10 which evaporator is prefer ably of the pressure welded sheet metal type and is mounted in the upper part of chamber 11 behind a movable closure member 13 therefor as is conventional in the art. An opening in the front of cabinet 10 provides access to chamber 11 and this opening is normally closed by an insulated door structure or wall section generally represented at 15 which is hingedly mounted on cabinet It) by suitable hinges for horizontal swinging movement relative thereto. The insulated wall section or door structure 15 comprises (see FIGURE 4) an outer metal panlike member 16, an inner molded plastic panel member 17, which may be dished or recessed inwardly for accommodating the mounting of door shelves thereon, and means other than insulation 18 between the members 16 and 17 for detachably securing them together. Door 15 also comprises a thin flexible nonmetallic sheet 19 intermediate the door members 16 and 17 and extending over the insulation 18 to provide a divider in the door or Wall section for a purpose to be hereinafter more fully described. Outer pan-like members 16 of door or wall section 15 has an inwardly bent flange 21 about the periphery thereof which is provided with internally threaded extrusions 22 forming tapped holes for receiving screws 23 to secure edges of members 16 and 17 together. The securing means or screws 23 pass through suitable holes provided near the edge of panel member 17 and in a lip or flanged portion of a rubber-like resilient gasket 24 whereby to secure the members 16 and 17 to one another, as well as to clamp gasket 24 on the door structure or insulated wall section 15.
Other insulated wall sections of cabinet 14) comprise an outer inverted substantially U-shaped sheet metal shelllike member 26 (see FlGURE 2) forming the exterior top and side surfaces of the cabinet and an inner metal box-like member or liner 27, spaced from member 26 forming walls of chamber 11. The inner surfaces of liner member 27 are preferably coated with porcelain enamel as is the practice in the art to render the interior of food chamber 11 readily cleanable. Insulating material 28, similar to the insulation 18 in door 15, is located between members 26 and 27 and substantially fills the space therebetween. A thin fiexile nonmetallic bag or sheet 29 is disposed intermediate members 26 and 27 and lies over the insulation 28 in contact with liner member 27. This wall section of the main body portion of cabinet also includes nonmetallic preferably molded plastic breaker strips 31 having a grooved inner edge overlapping the front edge portion of liner member 27 and having its outer edge fitted in a channel 32 formed in an inturned front portion 33 of shell 26. The breaker strips 31 extend around the throat of opening to chamber 11 and are detachably locked in place at corners of this opening by suitable gusset plates removably attached to cabinet 10 in any conventional manner now well known to those skilled in the art. Such removable gusset plates, together with the strips 31, form means for securing the forward edge part of liner member 27 to the front part of shell member 26. The fiat forward portion 33 of outer shell member 26 about the front of cabinet 10 provides a door jamb on the cabinet which is adapted to be abutted by gasket 24 on door for sealing the access opening of chamber 11. It is to be noted that bag or sheet 29 extends continuously along the inner surface of liner member 27 and breaker strips 31 to prevent bondage of the insulation to these elements and to thereby serve a purpose to be hereinafter described.
'In accordance with my invention it is desired to take advantage of the inherent properties or characteristics of a foamed plastic insulation whereby substantially lightweight insulated wall structures or sections can be made thinner and of increased structural strength while, at the same time, providing for the separation of certain elements in such structures or sections. For this reason I utilize a foamed-in-place polyurethane insulating material in combination With a thin sheet of polyethylene material to which such insulation does not adhere to accomplish the objects of my invention, as hereinbefore set forth, and to obtain other advantages. To this end it should be understood that different arrangements may be employed in the application of foamed polyurethane insulating material to wall structures or sections of a cabinet and thus I do not wish to be restricted to a specific application of the insulation to one or the other members of a wall section. For example, one member of a wall section to which the polyurethane insulation is to be foamed and bonded may be placed in a mold construction of. such material that the insulation will not adhere or bond thereto or the mold may be inserted into the body portion of a refrigerator cabinet. In either event there will be a space between the one member of the wall section and walls of the mold to be substantially filled by foaming the polyurethane insulation thereinto. After this insulation has been foamed in place and bonded to the one member of a wall structure or section, the nonadhering mold may be removed to permit assembly of other elements of the structure or section thereto. Conversely or on the other hand all elements of the wall structure or section may be assembled to one another with a thin flexible bag or sheet of polyethylene material added into the structure or wall section along surfaces of certain elements thereof to which the polyurethane insulation will not bond and then this insulation is foamed in the space between wall members of the completely assembled section or structure. Thus, it should be apparent that either of these alternative methads will suffice to accomplish the novelty of the present disclosure which is that of permitting one wall part or member to be separated and removed from another wall part or member of a wall section having plastic insulation foamed into the space between the members and bonded to at least one of them.
Referring now again to FIGURE 2 of the drawings, it will be noted that the polyethylene sheet 29 extends over the foamed polyurethane insulation 28 bonded to member 26 and along the inner surface of elements or parts of the cabinet wall section to be removed therefrom, if desired or required, and provides a divider between portions thereof to prevent bondage of the insulation thereto. The divider sheet 29 is impervious to air and moisture and provides a point of separation of wall members of the cabinet wall structure or section. Should the porcelain enamel coated metal liner member 27 become scratched, marred, chipped or damaged, it may be removed from cabinet 10, particularly from the foamed insulation 28 and divider sheet 29, and replaced by a new liner member. In order to remove the procelain coated liner member 27, the corner gusset plates holding the breaker strips 31 locked in place are first removed from cabinet 10 and then each of the strips 31 are detached from the wall section by sliding the edge part thereof, with a special tool, out of a channel 32 and slipping their other edge part away from the forward edge of liner 27 Since the polyethylene sheet 29 extends beyond liner member 27 over the inner surfaces of braker strips 31, the foamed insulation 28 is not bonded or adhered thereto and their removal is no problem. With these detachable securing means removed and since the polyethylene sheet 29 has prevented adhesion or bondage of the foamed polyurethane insulating material 28 to box-like liner member 27, this member may be pulled or slid outwardly from cabinet 10 in a straight-line direction paralleling the cabinet Wall section away from the foamed insulation 28 and shell member 26 to which the insulation is bonded (see FIGURE 3) to cause separation of the members of the wall section and removal of the damaged liner member 27 from the cabinet. A new porcelain enameled metal liner member 27 may be installed into cabinet 10 by reversing the operation of detaching the breaker strips 31 and the corner gussets The principle of separating one wall or panel member from another thereof in a cabinet wall section in which a foamed polyurethane insulating material is located between the members may also be adopted in the construction of the refrigerator cabinet door 15. Referring now to FIGURE 5 of the drawings I show a form of a door used on cabinet 10 wherein the metal pan-like outer member 16, together with a polyurethane insulation 18 foamed thereinto and bonded to its inner surfaces, has been removed from a mold in which the foaming of the insulation took place. In this form of door, the contour of the inner face of the insulation has been predetermined by the mold and a sheet 19 of polyethylene is placed over the face of insulation 18 to conform to its contour. The inner molded plastic panel member 17 is placed over sheet 19 and then the gasket 24 and detachable screws 23 are assembled to the door to secure the members 16 and 17 to one another so as to complete this cabinet wall section. If door panel member 17 becomes damaged in any manner it can, by virtue of sheet 19 forming a dividing point in the wall structure, be removed from pan member 16 and the foamed polyurethane insulation 18 bonded thereto to thereby separate the members 16 and 17 from one another. Panel-like member 17 is separable from the wall section along the polyethylene sheet 19, by removing the detachable securing means or screws 23, without disturbing, breaking or damaging the foam insulation 18, and a new panel member can therefore be readily replaced onto the wall section upon reattaching the screws.
In FIGURE 6 of the drawings 1 show a modified form of door at A wherein the pan-like outer member 16A, together with a polyurethane insulation 18A foamed therein and bonded to its inner surfaces to increase the structural strength of this part of the door or wall section has been removed from a mold in which the foaming of the insulation took place. In this modified wall section or door structure 15A the thickness of the foamed insulation 18A has been predetermined by walls of the mold and is flat and substantially flush'with the inturned flange 21A on door member 16A. A polyethylene sheet 19A is placed over the fiat surface of the foamed polyurethane insulation 18A and then the inner molded plastic panellike member 17A together with any suitable or desirable insulating material 28A, filling the cavities or recesses thereof and conforming to the fiat surfaces of the foam insulation, is placed over the structure. Thereafter the gasket 24 and detachable screws 23 are applied to the structure to removably secure elements of the door together. It is to be understood that in this modification the insulation 18A and 20A may be of different materials or they may be of like material such, for example, as the insulation 20A being polyurethane foamed into the inner molded plastic panel 17A. The polyethylene sheet 19A provides a divider or parting medium in wall or door structure 15A intermediate the members 16A and 17A. Should eitherv of the members 16A or 17A be damaged and require replacement, it can be separated or removed from the other member along or at sheet 19A by removing the detachable securing means or screws 23 from this modified wall section or door structure.
I show in FIGURE 7 of the drawings a further modified form of cabinet insulated wall'section or door structure 158 in which the section has its structural strength increased by a still different arrangement of foamed-in-place polyurethane insulation and wherein the outer metal pan member 16B is removable from the inner molded pastic door panel 173 and from the insulation 1813. In this modification the polyurethane insulating material may be foamed into the inner panel member 17B within a suitable mold and built up to the thickness desired therein so as to provide inclined edges protruding outwardly of member 17B. Filler strips 203 having tapered sides substantially conforming to the inclined edges of the insulation 18B are placed in door pan 16B along the sides thereof below flanges 21B thereon. The strips 20B can be of any suitable or desirable nonmetallic material of moderate insulating quality. After inserting strips 208 into pan member 16B, a thin sheet of polyethylene 19B is depressed against the flat inner face of member 16B and extended along the tapered sides of the inserted strips. Thereafter the inner panel member 1713, together with the layer of insulation 18B thereon and bonded thereto, is placed over the pan member and lowered so that the inclined side edges of the insulation 18B, protruding outwardly away from the inner panel 17B, snugly register with the polyethylene sheet along bounding strips 201-3. The elements or members of this wall section or door structure 15B are then secured together by the securing means or detachable screws 23. In this modified construction either wall or panel member 1613 or 17B are selectively separable and removable from one another and particularly outer pan member 163 with its inserts or strips 20B is removable from the insulation 183 by detaching the detachable screws 23.
From the foregoing it should be apparent that I have provided improved cabinet wall sections and door structures by utilizing foam plastic insulation therein to increase the structural strength thereof while at the same time providing a divider between portions or members of the sections or structures to one of which the strengthening insulation may be firmly bonded for permitting separation of the members. In addition, my invention presents several advantages in the use of foamed polyurethane insulating material in cabinet wall sections, particularly in conjunction with a polyethylene divider sheet in such sections. For example, the Freon" constituent or agent used as the medium to foam a plastic insulation such as polyurethane continues to be emitted therefrom for quite some time after the insulation is foamed in place. It is known that this Freon attacks and deteriorates other molded plastic members or elements, particularly those formed of polystyrene and similar compounds. Since polyethylene bags or sheets are impervious to moisture and gases, the use of such bags or sheets in the manner herein disclosed is highly advantageous. By covering certain plastic elements or members molded of polystyrene compounds, such as the cabinet breaker strips 31 and the molded plastic innerdoor panel member 17 with a layer of polyethylene material, these elements or members are isolated from the foamed polyurethane plastic insulation 18 and 28. The polyethylene sheets 19 and 29 form an impervious barrier between the insulation 18 and 28 and the elements or members 17 and 31 and these elements or members are consequently protected against Freon emitted from the polyurethane insulation. This protection is unique in that it preserves the elements or members 17 and 31 and prolongs the life thereof. In reality, the use of polyethylene bags or sheets as herein disclosed therefore serves a two-fold purpose in the construction of cabinet wall sections and cabinet door sections or structures by providing a divider therein to which the polyurethane insulation will not adhere for permitting separation or removal of members of these sections or structures from one another and of protecting other molded plastic elements or members included in their construction.
While the embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.
What is claimed is as follows:
1. A cabinet construction comprising, an outer shell member, a box-like liner member nested substantially within said shell member each having coextensive surfaces disposed in spaced-apart face-to-face relationship with insulation foamed into the space therebetween, said members having juxtapositioned preformed peripheral edge portions, said cabinet construction also comprising a divider layer of material extending between said peripheral edge portions and continuously over the inner face surface of said liner member adjacent the insulation preventing same from bonding to said liner member or said peripheral edge portions whereby said insulation bonds only to said outer shell member, said outer shell member and the insulation bonded thereto forming an inseparable permanent component of said cabinet construction cradling said box-like liner member, said box-like liner member defining Walls of a chamber in said cabinet having an access opening, and means interposed between said peripheral edge portions and removably interconnected with the preforming thereof for locking said liner member within said shell member, said unbonded box-like liner member being removable as a unit along said divider layer from said cabinet construction without fracturing the insulation of said permanent component thereof when said locking means is removed.
2. A cabinet construction comprising, an outer shell member, a box-like liner member nested substantially within said shell member each having coextensive surfaces disposed in spaced-apart face-to-face relationship from juxtapositioned peripheral edges with insulation foamed into the space therebetween, said cabinet construction also comprising a divider layer of material extending continuously over the inner face surface of one of said members adjacent the insulation preventing same from bonding thereto whereby said insulation bonds only to the other of said members, said other member and the insulation bonded thereto forming an inseparable permanent component of said cabinet construction cradling said box-like liner member, said box-like liner member defining walls of a chamber in said cabinet having an access opening, and means interposed between said members for locking said liner member within said shell member, said one unbonded member being removable as a unit along said divider layer from said cabinet construction without fracturing the insulation of said permanent component thereof when said locking means is ineffective to lock said liner member within said shell member.
3. A separable double walled cabinet structure compris- (a) an inner side member and an outer sheet metal side member providing opposed sides of said structure each having long wide coextensive surfaces directed inwardly of the double walled structure from juxtapositioned peripheral edges of said member,
(11) an edging part of said outer metal side member being flanged laterally thereof to provide an integral wall portion thereon bounding said double walled structure in the vicinity of said juxtapositioned edges of the members,
(c) the surfaces of said side members extending in spaced apart substantially parallel face-to-face relationship and having insulation foamed into the space therebetween,
(d) a layer of material to which the foamed insulation will not adhere disposed over said insulation inter-mediate same and one of said sidemembers of the double walled structure providing a separatortherein,
(e) said layer extending continuously along the inner face of said one side member throughout the length and Width of its long wide surface and overlapping said peripheral edge of the other of said side members of said double Walled structure,
(f) said separator preventing bonding of said insulation to said one side member whereby the insulation bonds only to the long wide inner face of said other side member paralleling the one side member and rendering said one unbonded member capable of removal from the structure,
(g) said other side member and the insulation bonded thereto forming an inseparable permanent component of said double walled structure for increasing its rigidity when the unbonded side member thereof is removed therefrom,
(11) means other than said insulation detachably interlocking edges of said one unbonded side member to said other member of the inseparable component of said double walled structure adjacent said integral bounding wall on said metal member'thereof, and
(i) the one unbonded side member of said double walled structure being upon detaching said detachable means removable at said separator from said other side member thereof without fracturing the insulation on said permanent component of the structure.
References Cited in the tile of this patent UNITED STATES PATENTS 2,106,840 Gould Feb. 1, 1938 2,552,641 Morrison May 15, 1951 2,629,698 Sterling Feb. 24, 1953 2,723,896 Wurtz Nov. 15, 1955 2,895,603 Freeman July 21, 1959 2,958,210 Rill Nov. 1, 1960